Coldest week of spring brings sub-zero temperatures and warnings for hard frosts
Arctic winds will push the mercury to minus 5C in parts over the coming days
Alaska megatsunami caused by mountain collapse was second largest EVER on record
The wave crested higher than the Eiffel Tower
Bone-dry winds and ramping temperatures threaten hay fever misery, with Britain on high pollen alert
Britons should make the most of the sunshine, with the bank holiday signalling a return of the rain
